The App::Cache module lets an application cache data locally. There are a few times an application would need to cache data: when it is retrieving information from the network or when it has to complete a large calculation.

For example, the Parse::BACKPAN::Packages module downloads a file off the net and parses it, creating a data structure. Only then can it actually provide any useful information for the programmer. Parse::BACKPAN::Packages uses App::Cache to cache both the file download and data structures, providing much faster use when the data is cached.

This module stores data in the home directory of the user, in a dot directory. For example, the Parse::BACKPAN::Packages cache is actually stored underneath "~/.parse_backpan_packages/cache/". This is so that permisssions are not a problem - it is a per-user, per-application cache.

The constructor creates an App::Cache object. It takes three optional parameters:

ttl contains the number of seconds in which a cache entry expires. The default is 30 minutes.

my $cache = App::Cache->new({ ttl => 30*60 });

application sets the application name. If you are calling new() from a class, the application is automagically set to the calling class, so you should rarely need to pass it in:

my $cache = App::Cache->new({ application => 'Your::Module' });

directory sets the directory to be used for the cache. Normally this is just set for you and will be based on the application name and be created in the users home directory. Sometimes for testing, it can be useful to set this.

my $cache = App::Cache->new({ directory => '/tmp/your/cache/dir' });

enabled can be set to 0 for testing, in which case you will always get cache misses:

Returns the full path to the cache directory. Primarily useful for when you are writing tests that use App::Cache and want to clean up after yourself. If you are doing that you may want to explicitly set the 'application' constructor parameter to avoid later cleaning up a cache dir that was already in use.